Faber and Touch Press's The Waste Land app is prospering with a premium price

How lucrative are iPad book-apps? UK studio Ustwo revealed some figures at Thursday's Futurebook Innovation Workshop conference in London indicating that gold-diggers should probably focus on other app categories for now.

The company's Nursery Rhymes With StoryTime was the highest grossing app in the App Store's Books category for a couple of weeks earlier this year, at a time when it was making around £2,000 a day. Not peanuts, by any means, but not the cascade of riches some optimistic publishers might be hoping for on Apple's store.

The Nursery Rhymes app has received a lot of press attention and repeated promotion from Apple, but Ustwo co-founder Mills told the conference that having spent £60,000 making the app, it has so far sold 37,339 copies for a total of £24,048 in revenue.

Ustwo was the only company to reveal its download and sales figures at Futurebook, which was notable for publishers showcasing innovative book-apps but remaining tight-lipped about the money those apps were making (or not making).

"Innovate now, don't think this is about making money now," Mills told the audience. "It's about pushing the medium forward. Have a lot of fun, and you'll benefit in the future."

One publisher that is currently making money is Faber, which has seen its iPad app for TS Eliot's The Waste Land ride high in the App Store charts, even with a £7.99 price. The app took Faber and its creative partner Touch Press just over a year to make, and includes audio readings, a video performance by actor Fiona Shaw, notes and original manuscript scans.

Faber's head of digital publishing Henry Volans voiced a key theme of the conference: the importance of partnerships between publishers and app developers. "Touch Press is not a developer and we are not their client," he said. "This is a partnership. If anything, we are both publishers."

Random House digital editor Dan Franklin agreed. "What creative agencies bring to the table is a completely different way of thinking about digital – more of a native way of thinking – and some of the partnerships like Touch Press and Faber are blowing everyone out of the water."

Authors loomed large in the discussion too, with publishers agreeing that the best book-apps come from collaboration with an engaged writer. Penguin's MyFry app for Stephen Fry was one example shown off during the event, while Pan Macmillan talked about working with Ken Follett on an ebook version of his Fall Of Giants novel with binaural sound accompanying the text.

HarperCollins Children's Books digital publishing manager Tom Conway outlined some of the challenges. "Working with the author is absolutely key, but it's also key that the author understand that it's not a book: it's a new storytelling thing," he said.

This principle is seen when turning original watercolour illustrations into animation for apps: Conway showed a clip of Paddington Bear as an example. "It's still the illustration, it's just a little bit magical and doesn't distract from the story".

The enthusiasm for the creative potential for book-apps was clear to see during the Futurebook event. However, the conference's final panel session showed that higher up the publishing chain, apps remain a sideline to executives' core focus on grappling with the wider shift to digital business models.

Apps were barely mentioned at all during this final session: hammering out ebook deals, restructuring internally and getting to grips with Kindle Store pricing and metadata still has more impact on a publisher's bottom line than releasing an innovative app.